revlog: move `offset_type` to `revlogutils` This multiple module are using this so it make sense to move it at the utility level. Differential Revision: https://phab.mercurial-scm.org/D10792

revlog: move entry documentation alongside new related constants Accessing individual index-entry element is usually done using integer directly. This is presumably for "performance reasons". However as the index entry gain more and more element it seems useful to get the option to use symbolic constant to access item, for both clarify and versatility. We will probably keep using integer for performance critical path, but less critical code may start using them now that they are declared. Differential Revision: https://phab.mercurial-scm.org/D10791

censor: drop size limitation on the tombstone This limitation seems to date back from a previous implementation of censors, were the revision were censored" in place. For a long while the implementation actually involved rewriting the revlog before replacing the original data. So it looks like we can safely remove this limitation. The tests suite agrees. Differential Revision: https://phab.mercurial-scm.org/D10790